Conventionally, a card reader has been widely used which performs reading of magnetic data recorded on a card and recording of magnetic data to a card. The card reader is, for example, mounted on a host device such as an ATM (Automate Teller Machine) which is installed and used in a financial institution such as a bank. Further, in the financial institutions in which the card reader is used, conventionally, a so-called skimming which means that a criminal attaches a magnetic head to a card insertion part of a card reader to illegally obtain magnetic data of a card by the magnetic head has been a serious problem.
In order to prevent this problem, a skimming device detection system has been proposed for detecting attachment of a skimming device including a magnetic head for skimming (hereinafter, referred to as a “skimming magnetic head”) to a card insertion part of an ATM (see, for example, Patent Literature 1). A skimming device detection system described in Patent Literature 1 includes an imaging device on which a lens having an autofocus control function is mounted. In the skimming device detection system, a transaction operation part of an ATM is image-pickuped by the imaging device to detect whether a skimming device is attached to a card insertion part or not on the basis of an image which is obtained by the imaging device.    [PTL 1] Japanese Patent Laid-Open No. 2008-225670
When the skimming device detection system described in Patent Literature 1 is used, it is possible to detect whether a skimming device is attached to a card insertion part or not. However, the skimming device detection system described in Patent Literature 1 is provided with the imaging device on which a lens having an autofocus control function is mounted and thus its structure is complicated.
Further, when the skimming device detection system described in Patent Literature 1 is used, an illegal act of a criminal is prevented. However, when the skimming device detection system is used for preventing an illegal act of a criminal, the skimming device detection system is required to be used together with the ATM. In other words, when this skimming device detection system is used, a large-scale apparatus is required.